Flatten Layers to Reduce Opex

As mobility, cloud computing, and the always-connected nature of the modern enterprise generate ever-increasing volumes of traffic at the network edge, the pressure to find better networking solutions increases. Chatsworth, CA-based MRV Communications believes they offer an answer for packet optical networks: the combination of historically disparate OSI layers for more agile, intelligent infrastructure.

The problem underlying most networks today is the complexity and expense incurred by large networks of connecting, back-to-back devices, often in the same site, according to MRV VP of Strategic Marketing Zeev Draer. "Customers require routing, which is in Layer 3, and Ethernet in Layer 2, and optical on Layer 1, so you have three layers and three devices involved in the same site," Draer said. Initial capex for all three devices aside, all that hardware results in significant opex, since, as Draer explained, "each device has its own connectivity to the management platform and consumes power and space."

Draer said that the model is becoming untenable enough to give rise to much discussion around how to handle it. That discussion, he added, "is really part of the Software Defined Networking mindset," since its proponents are looking to address similar network pain points. And among one of the answers being bandied about is the one MRV advocates: the collapsing of some OSI layers into single, more intelligent devices.

This convergence should prove particularly attractive to service providers because of its potential to reduce capex and opex. "Service providers are investing billions into their infrastructure, but their infrastructures are problematic business models because service provider revenue is shrinking while content provider revenue is increasing" along with traffic, Draer said. In his opinion, network devices capable of converging different layers can provide greater control, more efficient processing, and, ultimately, better levels of service.

In this model, improved speed and quality of service would come in large part from the greater agility of the infrastructure. "A basic problem today is that we've gone, in terms of activation of new service, from 90 days to 90 seconds," Draer said, so that "if my customer requests that I provision the service, I need to do it today, which is difficult" with a clunky, complex infrastructure spanning several different layers and departments. In theory, effective integration of network layers should result in faster, easier service provisioning, among other benefits.

Convergence of different layers and functions is already happening at carriers around the globe, according to Draer: "Some are consolidating their technicians, optical, and IT departments." Which department ends up in control of the new, consolidated department varies. Service devices that have already unified their functions can ease transitions into the new network management model and ensure its continued effectiveness, further reducing opex.

The bottom line in the model MRV advocates is the reduction of network complexity through the use of network devices that flatten down multiple OSI layers. Draer described the result of that flattening as a "glued layer that's intelligent enough to make decisions for different layers based on the current traffic and deliver it accurately based on traffic management, quality of service, and security implementations" normally assigned to disparate layers. And the benefits this confers will only continue to grow. "More intelligent design will continue to require fewer devices at the bottom line. Eventually, they'll implement different protocols on higher layers, with very integrated optical functionality," he said.

Naturally, MRV offers solutions designed to push this vision, such as its OptiSwitch 906G Series of carrier-class Ethernet demarcation service devices, which converge Layer 2 and Layer 3 services, and its OptiSwitch 9244-1210G packet-optical aggregation platform, which combines WDM optical layer and packet layer services. Both platforms share the same open source operating system and are controlled via MRV’s Pro-Vision service management software.

If layer convergence works the way its advocates claim, service providers and network managers will have a powerful way to control, provision, manage, and scale their networks, avoiding denial of service attacks and other consequences of an inefficient network. Will converged layers be the future of packet optical networks? MRV hopes so.